RAID which comes as REDUNDANT ARRAY OF INEXPENSIVE DISKS
It provides Disk Failures Protection.
RAID1,RAID5 are mechanisms we are supported in Teradata .
RAID1(Mirroring):
RAID1 is a RAID mechanism which maintains exact copy of VDisk on two or more disks .When any Disk fails respective duplicated disk will be available leading to high availability with no change in performance.Mirroring reduces available disk space by 50%
Advantages:
Drawback:
RAID5(PARITY):
RAID5 is a RAID mechanism in which DISK is made available by block level stripping and parity distribution. For making RAID5 atleast 3 DISKs are necessary.If a Disk is missing , data is made reconstructed from the missing disk with the help of Parity calculation formula.
P0 =B0+A0+C0
Parity reduces available disk space by 25%in 4 disk rank.Array controller reconstruction of failed disks longer than RAID1
Drawback:
Advantages :
It provides Disk Failures Protection.
RAID1,RAID5 are mechanisms we are supported in Teradata .
RAID1(Mirroring):
RAID1 is a RAID mechanism which maintains exact copy of VDisk on two or more disks .When any Disk fails respective duplicated disk will be available leading to high availability with no change in performance.Mirroring reduces available disk space by 50%
Advantages:
- Quick redirection
Drawback:
- Double memory
- Double operations
RAID5(PARITY):
RAID5 is a RAID mechanism in which DISK is made available by block level stripping and parity distribution. For making RAID5 atleast 3 DISKs are necessary.If a Disk is missing , data is made reconstructed from the missing disk with the help of Parity calculation formula.
P0 =B0+A0+C0
Parity reduces available disk space by 25%in 4 disk rank.Array controller reconstruction of failed disks longer than RAID1
Drawback:
- Difficult to continue
- Recovery takes time
Advantages :
- Reduced performance with disk failures
- Lower cost in terms of disk space